Hardened whetstone. Soak in sharpener oil before using. Size: 3.9 x 1.0 x 0.5 inches (10 x 2.5 x 1.3 cm); Individual package (package) Size: 1.2 x 3.9 x 0.8 inches (3.0 x 10.0 x 2.0 cm); Individual package (package) Weight: 3.5 oz (100 g); Made in Japan.